(1) Field of the Invention
The present invention relates to a wireless communication system, and more particularly to a mobile wireless communication system including a plurality of wireless base stations and base station controllers different in wireless communication method, and a monitoring apparatus.
(2) Description of Related Art
Recently, with the development of wireless communication technology, many types of mobile wireless communication systems different in communication method in terms of use frequency bands and modulation/demodulation method are proposed. For example, as a cellular communication system that applies the CDMA technology, a technical specification 1xEV-DO (1X Evolution Data Only) specific to data communication is known. The 1xEV-DO is included in cdma 2000 standards of wideband CDMA (W-CDMA) and enables data communication of up to 2.4 Mbps in a band of 1.25 MHz.
As a wireless communication system for hot spot, for example, there is Wi-Fi (Wireless Fidelity) proposed in IEEE802.11 belonging to standards of wireless LAN. As a wireless communication system suitable to broadband connection service in regions of relatively low population density, there is wireless MAN (Metropolitan Area Network) of IEEE802.16 standards, which is called WiMAX (Worldwide Interoperability for Microwave Access).
In IEEE P802.21 D00.04, standardization activities concerning handover among different types of wireless networks are performed, adopting above-described W-CDMA, 1xEV-DO, Wi-Fi, and WiMAX as mobile wireless communication methods eligible for handover to perform. The hand over of IEEEP802.21 D00.04 is called MIH (Media Independent Handover).
In recent years, a wireless communication system called “cognitive wireless” is studied. This system enables each wireless terminal or each wireless base station to select the most efficient mobile communication method in terms of frequency use efficiency and throughput characteristics by dynamically recognizing situations of wireless sections.